In an inelegant satellite suburb of Lille, Eric Balleux surveys his DIY domain with pride. This recently built addition to Castorama's Brico Depot chain represents DIY retail at its most basic.

'The products arrive in lorries. We simply unload them and put them on the shelves in their boxes,' he says. 'Our customers are mostly trade or large-scale DIY-ers. They know what they want. They can find it for themselves and they know that the way we can keep prices low is by cutting service to the minimum. They do not mind queuing to pay. They understand what it is that we are doing.'

Huge fluorescent signs highlight the prices in euros and francs. ('The exchange rate meant that suddenly all the products looked much more expensive. It's psychological.') The only service on offer is glass-cutting, roped off from the rest of the store to keep the customers out and so peg the floorspace within tight French planning guidelines (anything over 1,000 sq m needs special permission from the Government).

This is warehouse DIY in its most stripped-down format. Price is king. Shelves are never empty, says Balleux, because staff stock up at lunchtime when he shuts the doors. In France, no self-respecting tradesman works through the traditional two-hour midday break. Balleux would not open on a Sunday, even if French trading laws permitted it. The customers wouldn't come.

Half an hour up the road, Brico Depot's rather more glamourous big sister, Castorama, is closer to the DIY/home improvement store that a UK shopper would recognise. There is a reason for that, of course. The French 'did' superstores years before the Brits. Their hypermarkets precede Tesco and Safeway's prototypes by at least 15 years.

At the Castorama, in a much more affluent area than the Brico Depot, Antony Dore stresses the services on offer, from wallpapering or grouting classes on Saturday mornings to a picture-framing workshop. The kitchens are more varied and upmarket than Bricot's (though still cheap compared with their British counterparts), the showers look space-age, and everything is displayed with a view to attracting the untutored gaze of an average couple or family.

French shoppers are as keen as Brits on home improvement, but here the range on view is far greater. A huge swathe of floorspace is given over to bath mats, and countless types of wooden and laminated flooring compete for shoppers' attention.

Castorama's director of strategy and marketing, Christian Coq, says this is because French shoppers demand more variety. The desire to be different is, he says, entrenched. Many French people buy land and then build their own homes. Barratt-style developments are few and far between.

From store managers to group directors, the people behind France's number one DIY business acknowledge that there are British practices they admire. Coq cannot speak too highly of B&Q's Bill Whiting or his passion for the business.

But the message is clear: France is different. We know our customers. Hands off.